Chelsea manager Andre Villas-Boas has warned off Paris Saint-Germain coach Carlo Ancelotti over signing his former players.
Ancelotti, who was confirmed as the new PSG coach on Friday, left Stamford Bridge over the summer after two seasons at the club.
"Managers signing players from their old clubs is a situation that can happen," said Villas-Boas. "We tried to get Alvaro [Pereira from Porto] but couldn't.
"There's always that possibility because you get to know people from the past,
but we have no interest in selling those players. They're not for sale."
Chelsea, who are currently fourth in the Premier League table, host Aston Villa on New Year's Eve.